heater is blowing cold air when on hot have replaced radiator and flushed? on 2000 Ford Expedition

what could cause this and do you have a D.I.Y. solution to this issue.is this a common problem

by in Manchester, NH on January 08, 2014
2 answers
ANSWER by on January 08, 2014
Check the heater to ensure the trash you just flushed didn't go into the core and stop it up as well. Next would be to check/test the temp/blend door actuator.
ANSWER by on January 09, 2014
also ck coolant level